1. Field of the Invention
The invention relates to the contact-free or touchless transmission of condition responsive electrical signals from a rotating machine part to a stationary machine part as it may be used for measuring and control of the temperature of a rotating heated or cooled roll in a yarn treating machine.
2. Brief Description of the Background of the Invention Including Prior Art
Apparatus of this type is shown in German patents 29 49 075 and 36 21 397.
German Patent document 2,949,075 teaches an arrangement for contact-free temperature measurement at a rotating machine part. In comparison to this reference, the instant invention does not only disclose an expansion to several temperature resistors and their scanning with the aid of a multiplexer but also the means for synchronization of the scanning of the measurement values on the rotating machine part with signal evaluation on the stationary machine part.
The German Patent document 3,621,397 teaches a heat cylinder with measurement value transmission of several temperature-dependent resistors. A co-rotating scanner scans the resistors. For a transmission, at least three separate transmission devices are required, namely, a first one for the supplying of current to the rotating transformer, a second one for transmitting the temperature signals to the stationary part, and a third one for the synchronization of the rotating scanner by a stationary pulse indicator.